1. Field of the Invention
The present invention relates to an ink tank coupling method for use with a liquid ejection recording apparatus in which a liquid such as ink is ejected to carry out recording, an ink jet recording apparatus, and an ink tank for use in the ink jet recording apparatus. More particularly, the present invention relates to an ink tank coupling method for use with a liquid ejection recording apparatus which is employed in an ink jet printing system consuming a large amount of ink, an ink jet recording apparatus, and a large-capacity ink tank mounted on the ink jet recording apparatus.
2. Description of the Related Art
An ink tank (liquid storing container) for use in an ink jet recording apparatus is constructed to be detachably attached to an ink tank unit, which serves as an ink tank receiving portion of the recording apparatus, in order that the ink tank can be easily replaced when ink is exhausted. The ink tank has an ink supply port which is closed by a rubber plug to prevent leakage of ink when the ink tank is handled alone. The ink tank unit includes a hollow needle or the like which is provided in its connecting portion to the ink tank. By connecting the ink tank unit to the ink supply port of the ink tank, ink can be supplied from the ink tank.
Japanese Patent Laid-Open No. 1-141750, for example, discloses a detailed construction of an ink tank unit which enables such an ink tank to be mounted on an ink jet recording apparatus, and an ink tank coupling method. According to the known related art as disclosed in that publication, the ink tank has an ink supply port provided in its front portion taking in the direction in which the ink tank is inserted into the ink tank unit so that the direction in which the ink tank is inserted into the ink tank unit is the same as the direction in which the ink supply port of the ink tank is connected to an ink supply path in the ink jet recording apparatus. When coupling the ink tank unit and the ink tank with each other, positioning of the ink tank relative to the ink tank unit and insertion of the hollow needle into the ink supply port are effected with one action.
The direction in which the ink tank is inserted into the ink tank unit depends on the shape and size of the ink tank. In some cases, the ink tank is horizontally inserted into the ink tank unit as disclosed in the above-mentioned Japanese Patent Laid-Open No. 1-141750, and in other cases, the ink tank is ventrally inserted into the ink tank unit from above as disclosed in Japanese Patent Laid-Open No. 9-076525. In any case, the direction in which a needle is inserted is opposed to the direction in which the ink tank is inserted.
Meanwhile, in a large-sized ink jet recording apparatus having a high printing duty and consuming a large amount of ink, a large-capacity ink tank capable of containing an amount of ink, for example, not less than 200 cc, more preferably not less than 500 cc, is often employed to hold down the frequency of replacement of ink tanks.
With a container having such a large size, however, the following specific problems due to an increase of the container size arise in point of connection to an ink tank unit.
Specifically, because the container contains a large amount of liquid and the container including the liquid has large total weight, users sometimes cannot clearly recognize whether an ink supply needle is appropriately connected at the same time as upon the container being attached to the ink tank unit, including even the case that the needle and an ink supply port are shifted in positional relationship between them. As a result, an extra force is imposed on a coupled portion between the container and the ink supply unit due to a condition where the needle and the ink supply port are not positively connected to each other. This raises a risk that ink may leak from the coupled portion, or in the worst case, the coupled portion may be damaged; for example, the needle may be bent.
Also, because of the above-mentioned container having a large size, if an ink tank is designed to be positioned to a point remote from the coupled portion when attached to the recording apparatus, the container is required to be manufactured with high accuracy in order to realize positive coupling.
Particularly, in such a construction that the direction in which the needle is inserted is opposed to the direction in which the ink tank is inserted, if the ink tank is fixed offset from a predetermined position, an extra force is imposed on the coupled portion due to a condition where the needle and the ink supply port are not positively connected to each other, thus resulting in a risk that ink may leak from the coupled portion, or in the worst case, the coupled portion may be damaged; for example, the needle may be bent.